题目描述
Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.
Example 1:
Input: 121
Output: true
Example 2:
Input: -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.
Example 3:
Input: 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.
Follow up:
Coud you solve it without converting the integer to a string?
Qiang的思路
class Solution:
def isPalindrome(self, x: int) -> bool:
if x < 0:
return False
_x = x
tmp = 0
while x != 0:
tmp = tmp * 10 + x % 10
x = x // 10
return tmp == _x
class Solution {
public:
bool isPalindrome(int x) {
if(x < 0)
return false;
int _x = x;
long long tmp = 0;
while(_x != 0){
tmp = tmp * 10 + _x % 10;
_x = _x / 10;
}
return x == tmp;
}
};
